Malaria is the leading cause of death in Uganda. Children and pregnant women are most vulnerable, but the blood tests that help diagnose it are invasive, expensive and time consuming. It means that half of all malaria deaths continue to be in children aged under five. Software engineer Brian Gitta became determined to turn this statistic on its head after malaria forced him to miss lectures at university. Along with six student friends – all of whom have been infected several times with malaria – he developed a low-cost, reusable device that can test for the disease quickly and accurately, without drawing blood. Matibabu – “medical centre” in Swahili – clips on to the patient’s finger and shines a red beam of light on to the skin, detecting changes in the shape, colour and concentration of red blood cells, all of which are affected by malaria.